Komatsu WB91-93 User Manual

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WEBM000404

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PC15R-8

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10 STRUCTURE AND FUNCTION........................................................................................ 10-1

20 TESTING AND ADJUSTING ............................................................................................ 20-1

30 DISASSEMBLY AND ASSEMBLY.................................................................................. 30-1

40 MAINTENANCE STANDARD........................................................................................... 40-1

WB91R-2 WB93R-2

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WB91R-2 WB93R-2

Page 7

IMPORTANT SAFETY NOTICE

Proper service and repair is extremely important for the safe operation of your machine. The service andrepair techniquesrecommended byKomatsu Utility anddescribe in thismanual areboth effective and safe methods of operation.Some of these operations require the use of tools speciallydesigned by Komatsu Utility for the purpose. To prevent injury to workers, the symbols and are used to mark safety precautions in this manual. The cautions accompanyingthese symbolsshould alwaysbe carefullyfollowed. Ifany dangerarises ormay possibly arise, first consider safety, and take necessary steps to face.

SAFETY

GENERAL PRECAUTIONS

Mistakes in operation extremely dangerous. Read all the Operation and Maintenance Manual carefully BEFORE operating the machine.

1. Before carrying out anygreasing or repairs,read all theprecautions writtenon thedecals whichare suck on the machine.

2. Whencarrying outany operation, alwayswear safety shoes and helmet. Do not wear loose work clothes, or clothes with buttons missing.

• Always wear safety glasses when hitting parts

with a hammer.

• Always wear safety glasses when grinding

parts with a grinder, etc.

3. If welding repairs are needed, always have a trained, experienced welder carry out the work. When carryingout welding work, alwayswear welding gloves, apron, glasses, cap and other clothes suited for welding work.

4. When carrying out any operation with two or more workers, always agree on the operating procedure before starting. Always inform your fellow workers before starting any step of the operation. Before starting work, hang UNDER REPAIR signs on the controls in the operator’s compartment.

5. Keepall toolsin goodcondition andlearn thecorrect way to use them.

6. Decide a place in the repair workshop to keep tools and removedparts. Always keep thetools andparts in their correct places. Always keep the work area clean andmake surethat thereis nodirt or oilon the floor. Smoke onlyin the areasprovided forsmoking. Never smoke while working.

PREPARATIONS FOR WORK

7. Before adding or making any repairs, park the machine onhard, level ground,and blockthe wheels to prevent the machine from moving.

8. Before starting work, lower outrigger, bucket or any other work equipment to the ground. If this is not possible, use blocksto prevent thework equipment from falling down. In addition, be sure to lock all the control levers and hang warning sign on them.

9. When disassembling or assembling, support the machine withblocks, jacks or standsbefore starting work.

10. Remove allmud andoil fromthe stepsor otherplaces used to get on and off the machine. Always use thehandrails, laddersor stepswhen gettingon oroff the machine. Never jump on or off the machine. If it is impossible to use the handrails, ladders or steps, use a stand to provide safe footing.

PRECAUTIONS DURING WORK

11. When removing the oil filler cap, drain plug or hydraulic pressure measuring plugs, loosen them slowly to prevent the oil from spurting out. Before disconnecting or removing components of the hydraulic circuit and engine cooling circuit, first remove the pressure completely from the circuit.

12. The water and oilin thecircuits are not hot whenthe engine in stopped, so be careful not to get burned. Wait for the oil water to cool before carrying out any work on the cooling water circuits.

13. Before startingwork, removethe leadsfrom the battery. Always remove thelead from the negative (– ) terminal first.

SAFETY

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Page 8

SAFETY

14. When raising heavy components, use a hoist or crane. Check that the wire rope, chains and hooks are free from damage. Always use lifting equipment which has ample capacity. Install the lifting equipment at the correct places. Use a hoist or crane and operate slowly to prevent the component from hitting any other part. Do not work with any part still raised by the hoist or crane.

15. When removing covers which are under internal pressure or under pressure from a spring, always leave twobolts inposition on oppositesides. Slowly release thepressure, then slowly loosenthe boltsto remove.

16. When removing components, be careful not to break or damage the wiring. Damage wiring may cause electrical fires.

17. When removingpiping, stopthe fuelor oil fromspillingout. Ifany fuelor oildrips onto thefloor, wipeit up immediately. Fuel or oil on the floor can cause you to slip, or can even start fires.

18. As ageneral rule,do notuse gasolineto washparts. In particular, use only the minimum of gasoline when washing electrical parts.

19. Be sure to assemble all parts again in their original places. Replace any damage parts with new parts. When installing hoses and wires, be sure that they will not be damaged by contact with other parts when the machine is being operated.

20. When installing high pressure hoses, make sure that they are not twisted. Damaged tubes are dangerous, so be extremely careful when installing tubes for high pressure circuits. Also, check that connecting parts are correctly tightened.

21. When assembling or installing parts, always use specified tightening torques. When installing the parts which vibrate violently or rotate at high speed, be particulary careful to check that they are correctly installed.

22. When aligning two holes, never insert your fingers or hand.

23. When measuring hydraulicpressure, checkthat the measuring toolis correctlyassembled beforetaking any measurement.

24. Take sure when removing or installing wheels.

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WB91R-2 WB93R-2

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FOREWORD

This shop manual has been prepared as an aid to improve the quality ofrepairs by giving the operator an accurate understanding of the product and by showing him the correct way to perform repairs and make judgements. Make sure you understand the contents of this manual and use it to full effect at every opportunity.

This shop manual mainly containsthe necessary technical informationfor operations performed in a service workshop.

The manual is dividedinto chapters on each maingroup of components;these chapters are further divided intothe following sections.

STRUCTURE AND FUNCTION

This sectionexplains thestructure andfunction of eachcomponent. It serves notonly togive an understanding of the structure, but also serves as reference material for troubleshooting.

TESTING AND ADJUSTING

This sections explains checks to be made before and after performing repairs, as well as adjustments to be made at completion of the checks and repairs. Troubleshooting charts correlating «Problems» to «Causes» are also included in this section.

DISASSEMBLY AND ASSEMBLY

This section explains the order to be followed when removing, installing, disassembling or assembling each component, as well as precautions to be taken for these operations.

MAINTENANCE STANDARD

This section gives the judgement standards when inspecting disassembled parts.

NOTE

The specifications contained in this shop manual are subject to change at any time and without any notice. Contact your Komatsu Utility distributor for the latest information.

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HOW TO READ THE SHOP MANUAL

VOLUMES

Shop manual are issued as a guide to carry out repairs. These various volumes are designed to avoid duplicating the same information.

DISTRIBUTION AND UPDATING

Any additions, amendments or other changes will be sent to Komatsu Utility distributors. Get themost up-to-dateinformation before you startany work.

FILING METHOD

1. See the page number on the bottom of the page. File the pages in correct order.

2. Following examplesshow you howto readthe page number. Example:

Item number (10. Structure and Function)

Consecutive page number for each item

SYMBOLS

In order to make the shop manual greatly chelpful, important points about safety and quality are marked with the following symbols.

Symbol Item Remarks

Special safety precautions are necessary when performing the work.

★

Safety

Caution

Weight

Tightening

torque

Extra special safety precautions are necessary when performing the work because it is under internal pressure.

Special technical precautions or other precautions for preserving standards are necessary when performing the work.

Weight of parts or systems. Caution necessary when selecting hoisting wire, or when working posture is important, etc.

Parts that require special attention for the tightening torque during assembly.

3. Additional pages: additional pagesare indicated by a hyphen (–) and number after the page number. Fle as in the example. Example:

10-4

10-4-1

Added pages

10-4-2

10-5

REVISED EDITION MARK

➀ ➁ ➂ ....)

(

When a manual is revised, an edition mark is recorded on the bottom outside corner of the pages.

REVISIONS

Revised pages areshown on the LIST OFREVISED PAGES between the title page and SAFETY page.

Coat

Oil, water

Drain

Parts to be coated with adhesives and lubricants etc.

Places where oil, water or fuel must be added, and their quantity.

Places where oil or water must be drained, and quantity to be drained.

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HOISTING INSTRUCTIONS

Heavy parts (25 kg or more) must be lifted

with a hoist etc. In the

section, every part weighing 25 kg or more is

bly

clearly indicated with the symbol

1. If a part cannot be smoothly removed from the machine by hoisting, the following checks should be made:

• Check for removal of all bolts fastening the part

to the relative parts.

• Check for any part causing interference with

the part to be removed.

2. Wire ropes

1) Use adequate ropes depending on the weightof

parts to be hoisted, referring to the table below:

(Standard «S» or «Z» twist ropes

without galvanizing)

Rope diameter (mm) Allowable load (tons)

10.0

11.2

12.5

14.0

16.0

18.0

Disassembly and Assem-

WIRE ROPES

1.0

1.4

1.6

2.2

2.8

3.6

HOISTING INSTRUCTIONS

Hooks have maximum strength at the middle portion.

3) Do not sling a heavy load with one rope alone, but sling with two or more ropes symmetrically wound on to the load.

Slingingwith one rope maycause turningof theload during hoisting, untwistingof the rope, or slipping of the rope from its original winding position on the load, which can cause dangerous accidents.

4) Do not sling a heavy load with ropes forming a wide hanging angle from the hook. When hoisting a load with two or more ropes, the force subjected to each rope will increase with the hanging angles. The table below shows the variation of allowable load (kg) when hoisting is made with two ropes, each of which is allowed to sling up to 1000 kg vertically, at various handing angles. When tworopes slinga loadvertically, upto 2000kg of total weight can be suspended. This weight becomes 1000 kg when two ropes make a 120° hanging angle. On the otherhand,two ropesaresubjected toan excessiveforce aslarge as4000 kgif theysling a2000 kg load at a lifting angle of 150°.

20.0

22.4

30.0

40.0

50.0

60.0

The allowable load value is estimated to be onesixth or one-seventh of the breaking strength of the rope used.

2) Slingwire ropesfrom themiddle portionof thehook. Slinging near the edge of the hook may cause the rope to slip off the hook during hoist rious accident can result.

4.4

5.6

10.0

18.0

28.0

40.0

ing, and a se-

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STANDARD TIGHTENING TORQUE

The following charts give the standard tightening torques of bolts and nuts. Exceptions are given in section of «Disassembly and Assembly».

1. STANDARD TIGHTENING TORQUE OF BOLTS AND NUT

Width across flat

Thread

diameter ofbolts

(mm)

Pitch of

bolts

(mm)

kgmNmkgmNm

STANDARD TIGHTENING TORQUE

1.25

1.5

1.75

2.5

3.5

0.96

2.3

4.6

7.8

12.5

19.5

96±10

131

±0.1

±0.2

±0.5

±0.8

±1

±2

±3

±4

±6

±7

±14

9.5

122

191

262

372

511

644

945

1287

±1

±2

±4.9

±8

±13

±21

±28

±40

±57

±70

±100

±140

1.3

3.2

6.5

17.5

135

184

±0.15

±0.3

±0.6

±1

±3

±4

±6

±8

±10

±15

±20

±2

13.5

32.2

108

172

268

366

524

719

905

1329

1810

±1.5

±3.5

±6.5

±11

±18

±29

±36

±57

±80

±98

±140

±190

This torque table does not apply to bolts or nuts which have to fasten nylon or other parts non-ferrous metal washer.

3.5

----

177

230

295

±20

±25

±33

1740

2250

2900

±200

±250

±330

250

320

410

±27

±35

±45

2455

3150

4050

±270

±350

±450

★ Nm (newton meter): 1 Nm = 0.102 kgm

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Page 13

2. TIGHTENING TORQUE FOR NUTS OF FLARED

Use these torques for nut part of flared.

STANDARD TIGHTENING TORQUE

Thread diameter

of nut part

(mm)

1/2” -20

9/16” -18

3/4” -16

7/8” -14

1.1/16 - 12

1.5/16 - 12

1.5/8 - 12

Width across flats

of nut part

(mm)

TIGHTENING TORQUE

kgm Nm

2.6

6.7

9.7

±0.5

±2

±3

±5

±2

±5

Sealing surface

25.5

39.2

65.7

78.5

95.15

166.7

196.2

78.5

196.2

±4.9

±19.6

±29.4

±49

±19.6

±49

Thread diameter

of nut part

(mm)

9/16” -18

11/16” -16

13/16” -16

1” -14

1.3/16 - 12

1.7/16 - 12

1.11/16 - 12

2” -12

WB91R-2 WB93R-2

Width across flats

of nut part

(mm)

TIGHTENING TORQUE

kgm Nm

2.3–2.5

3.4–3.9

5.2–5.8

8.2–9.2

12.2–13.3

15.3–17.3

18.4–20.4

20.4–24.4

23–25

33–38

51–57

80–90

120–130

150–170

180–200

200–240

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Page 14

COAT I NG M ATER I A LS

COATIN G MAT ERIAL S

The recommended coating materials prescribed in Komatsu Utility Shop Manuals are listed below:

Nomenclature Code Applications

ASL800010 Used to apply rubber pads, rubber gaskets and cork plugs.

Adhesives

Gasket sealant

ASL800020

Loctite 222 Used for low resistance locking of screws, check nuts and adjustment nuts.

Loctite 242

Loctite 262 Used forhigh resistantof threadedparts thatcan be removed with normal tools.

Loctite 270

Loctite 542 Used for sealing the union threads for hydraulic tubes.

Loctite 573

Loctite 601

Loctite 675

ASL800060

Loctite 510

Used to apply resin,rubber, metallicand non-metallicparts whena fast,strong seal is needed.

Toprevent theloosening ofbolts, nutsand plugsand the leakageof oil.Used for medium resistance locking of screws and nuts of every type, and for locking keys and bearings.

Used for high resistant locking and for sealing threaded parts, bolts and stud bolts.

Used forsealing ratherexact planesurfaces whenthe optionof possiblefuture dismantling is required.

Used forhigh resistantlocking ofmechanical componentsthat canbe removed only after heating

Used to lock cylindrical couplings and for the permanent locking of threaded parts, and also to lock shafts to bearings, gears, pulleys, pins, bushings, etc.

Used by itself to seal grease fittings, tapered screw fittings and tapered screw fittings in hydraulic circuits of less than 50 mm in diameter.

Used by itself on mounting flat surface (Clearance between surfaces within 0.2 mm)

Antifriction compound (Lubricant including Molybdenum disulfide)

Grease (Lithium grease)

Vaseline

00-10

Loctite 518

ASL800040

ASL800050

-----

Used by itself on mounting flat surface (Clearance between surfaces within 0.5 mm

Applied to bearings and taper shaft to facilitate press-fitting and to prevent sticking, burning or rusting.

Applied to bearings, sliding parts and oil seals for lubrication, rust prevention and facilitation of assembling work.

Used for protecting battery electrode terminals from corrosion

WB91R-2 WB93R-2

Page 15

ELECTRIC WIRE CODE

ELECTRIC

In the wiring diagrams various colour and symbols are employed to indicate the thickness of wires. This wire code table will help you understand WIRING DIAGRAMS. Example: R–N 1.5 indicates a cable having a nominal number 1.5 and red coating with black stripe.

CLASSIFICATION BY THICKNESS

Nominal

number

0.5 16 0.20 0.35 1.55 3.5 1 14 0.30 0.99 2.80 11

1.5 21 0.30 1.48 3.35 14

2.5 35 0.30 2.47 3.80 20 4 56 0.30 3.95 4.60 28 6 84 0.30 5.93 5.20 37

10 84 0.40 10.55 7.10 53 50 399 0.40 50.11 14 160

Number

strands

Copper wire Ø of strands

(mm)

Cross section

(mm)

Cable O.D.

(mm)

Current rating

(A)

CLASSIFICATION BY COLOUR AND CODE

Primary Auxiliary Code A A–BA/BA–G – A–NA/NA–RA/RA–VA/V Colour Light Blue Light Blue–White Light Blue–Yellow Light Blue–Black Light Blue–Red Light Blue–Green Code B B–G – B–NB/NB–RB/R – B/V –– Colour White White–Yellow White–Black White–Red White–Green – Code C C–BC/BC–L – C–N ––––– Colour Orange Orange–White Orange–Blue Orange–Black –– Code G G–NG/NG–R – G–V ––––– Colour Yellow Yellow–Black Yellow–Red Yellow–Green –– Code H H–G – H–L – H–NH/NH–R ––– Colour Grey Grey–Yellow Grey–Blue Grey–Black Grey–Red – Code L L–BL/BL–G ––L/N –––– Colour Blue Blue–White Blue–Yellow Blue–Black –– Code M M–B – M–NM/NM–V ––––– Colour Brown Brown–White Brown–Black Brown–Green –– Code N –––––––––– Colour Black ––––– Code R R–G – R–NR/NR–V ––––– Colour Red Red–Yellow Red–Black Red–Green –– Code S S–G – S–N ––––––– Colour Pink Pink–Yellow Pink–Black ––– Code V V–B – V–NV/N –––––– Colour Green Green–White Green–Black ––– Code Z Z–BZ/BZ–NZ/N –––––– Colour Violet Violet–White Violet–Black –––

COMPOSITION OF THE COLOURS

The coloration of two-colour wires is indicated by the composition of the symbol listed. Example: G–V = Yellow-Green with longitudinal colouring

G/V = Yellow-Green with transversal colouring

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Page 16

WEIGHT TABLE

This weight table is a guide for use when transporting or handling components.

Unit: kg

Machine model WB91R-2 WB93R-2 From serial number 91F20145 93F23453 Engine assembly - Muffler - Exhaust pipe 400 410 Radiator - exchanger 37 37 Hydraulic oil tank (empty) 77 77 Fuel tank (empty) 73 73 Front counterweight 300 300 Engine hood 27 27 Cabin (without seat) 595 595 Seat 34 34 Engine-gear box-pump group 730 740 Piston pump 28 28 Transmission 230 230 Front axle 316 316 Rear axle 511 511 Front wheel

Rear wheel 2-spool control valve

3-spool control valve Work equipment

• Boom

• Bucket

• Fulcrum lever

• Tilt lever

• Raise cylinder

• Tilt cylinder

Work equipment

• with standard arm

• with long arm

• with jig arm

Boom 323 323 Arm 213 213 Long arm 245 245 Boom swing bracket 133 133 Backframe 237 237 Control valve (6-spool) 47 47 Control valve (7-spool) 53 53 Control valve (8-spool) 59 59 Jig arm 392 392 Outriggers 57 57 Boom cylinder 65 78 Arm cylinder 69 69 Bucket cylinder 49 49 Outriggers cylinder 42 42 Swing cylinder 30 30 Bucket 156 156

163

24 30

960 370

427 13x4 48x2 40x2 45x2

850

885 1030

163

24 30

960 370

427 13x4 48x2 40x2 45x2

850

885 1030

00-12

WB91R-2 WB93R-2

Page 17

TABLE OF OIL AND COOLANT QUANTITIES

RESERVOIR

Crankcase sump

Hydraulic circuit

Hydraulic circuit with biodegradable oil

Front axle

• Differential

• Final reduction gear

(each.)

Rear axle:

• Differential

KIND OF

FLUID

OIL

• API CD

OIL

• API CD

OIL

• UTTO FLUID

AMBIENT TEMPERATURE CAPACITY (

--30--20--

SAE 10W

1001020304050°C

SAE 20W-20

SAE 30

SAE 40

SAE 10W-30

ᐉ)

Specified Refill

7.9 7.9

150 92

6.5 6.5

14.5 14.5

• Final reduction gear (each.)

Hydraulic transmission

Braking system

Fuel tank DIESEL OIL 130 –

Engine coolant system

OLIO

GM DEXRON® II D (DEXRON® is a registered General Motors Corporation)

✽

ASTM D975 N.2

WATER + ANTI-FREEZE

WATER 14 –

PERMANENT LIQUID

1.5 1.5

20 17

0.8 0.8

14 –

✽ ASTM D975 N.

ASTM: America Society of Testing and Materials SAE: Society of Automotive Engineers API: American Petroleum Institute MIL: Military Specification CCMC: Common Market Constructors Committe

First filling quantity:

total quantity of oil, including the oil for the components and pipes.

Oil change quantity:

quantity of oil necessary to fill the system or unit during the normal inspection and maintenance operations.

WB91R-2 WB93R-2

00-13

Page 18

TABLE OF OIL AND COOLANT QUANTITIES

NOTE:

(1) When the diesel oilsulphur content isless then 0.5%, change the engine oilaccording to theperiodic maintenance

intervals indicated in the operationand maintenancemanual. Inthe dieseloil sulphurcontent exceeds0.5% change the engine oil according to the following table:

Sulphur content Engine oil change interval

from 0.5 to 1.0% 1/2

over 1.0% 1/4

(2) When startingthe engineat temperatures below0 °C, useengine oil SAE10W, 20W-20 and 10W-30,even if during

the day the temperature increases by 10 °C.

(3) Use engineoil with CD classification; ifoil with CD classificationis used, reduce the engineoil change interval by a

half.

(4) Use originalproducts, which havecharacteristics specifically formulatedand approvedfor theengine, the hydraulic

circuit of equipment and for reductions.

of regular interval of regular interval

00-14

WB91R-2 WB93R-2

Page 19

CONVERSION TABLE

METHOD OF USING THE CONVERSION TABLE

Theconversiontableinthissectionisprovidedtoenablesimpleconversionoffigures. For details of the method of using the conversion table, see the example given below.

EXAMPLE

• Method of using the conversion table to convert from millimeters to inches.

1. Convert 55 mm into inches.

CONVERSION TABLE

0.236

0.630

1.024

, then drow a horizontal line from

1 mm = 0.03937 in.

0.276

0.669

1.063

0.315

0.709

1.102

0.354

0.748

1.142

1 - Locate the number 50 in the vertical column at the left side, take this as

2 - Locate the number 5 in the row across the top, take this as , then draw a perpendicular line down from .

3 - Take the point where the two lines cross as . This point gives the value when converting from mil-

limeters to inches. Therefore,

2. Convert 550 mm into inches

1 - The number 550 does not appearin the table, so divide by 10 (move the decimal point one place to the left) to

convert it to 55 mm.

2 - Carry out the same procedure as above to convert 55 mm to 2.165 in.

3 - The originalvalue (550 mm) wasdivided by10, somultiply 2.165in. by 10(move the decimalpoint one placeto

the right) to return to the original value. This gives 550 mm = 21.65 in.

From millimeters to inches

0 1 2 3 4 5 6 7 8 9

0.039

0.433

0.827

0.394

0.787

55 mm =2.165 in.

0.079

0.472

0.866

0.118

0.512

0.906

C C

0.157

0.551

0.945

0.197

0.591

0.984

1.181

1.575

1.969

2.362

2.756

3.150

3.543

WB91R-2 WB93R-2

1.220

1.614

2.008

2.402

2.795

3.189

3.583

1.260

1.654

2.047

2.441

2.835

3.228

3.622

1.299

1.693

2.087

2.480

2.874

3.268

3.661

1.339

1.732

2.126

2.520

2.913

3.307

3.701

1.378

1.772

2.165

2.559

2.953

3.346

3.740

1.417

1.811

2.205

2.598

2.992

3.386

3.780

1.457

1.850

2.244

2.638

3.032

3.425

3.819

1.496

1.890

2.283

2.677

3.071

3.465

3.858

1.536

1.929

2.323

2.717

3.110

3.504

3.898

00-15

Page 20

From mm to in.

CONVERSION TABLE

1 mm = 0.03937 in.

0123456789

From kg to lb.

0.394

0.787

1.181

1.575

1.969

2.362

2.756

3.150

3.543

0.039

0.433

0.827

1.220

1.614

2.008

2.402

2.795

3.189

3.583

0.079

0.472

0.866

1.260

1.654

2.047

2.441

2.835

3.228

3.622

0.118

0.512

0.906

1.299

1.693

2.087

2.480

2.874

3.268

3.661

0.157

0.551

0.945

1.339

1.732

2.126

2.520

2.913

3.307

3.701

0.197

0.591

0.984

1.378

1.772

2.165

2.559

2.953

3.346

3.740

0.236

0.630

1.024

1.417

1.811

2.205

2.598

2.992

3.386

3.780

0.276

0.669

1.063

1.457

1.850

2.244

2.638

3.032

3.425

3.819

0.315

0.709

1.102

1.496

1.890

2.283

2.677

3.071

3.465

3.858

1 kg = 2.2046 lb.

0.354

0.748

1.142

1.536

1.929

2.323

2.717

3.110

3.504

3.898

0123456789

22.05

44.09

66.14

88.18

110.23

132.28

154.32

176.37

198.42

2.20

24.25

46.30

68.34

90.39

112.44

134.48

156.53

178.57

200.62

4.41

26.46

48.50

70.55

92.59

114.64

136.69

158.73

180.78

202.83

6.61

28.66

50.71

72.75

94.80

116.85

138.89

160.94

182.98

205.03

8.82

30.86

51.91

74.96

97.00

119.05

141.10

163.14

185.19

207.24

11.02

33.07

55.12

77.16

99.21

121.24

143.30

165.35

187.39

209.44

13.23

35.27

57.32

79.37

101.41

123.46

145.51

167.55

189.60

211.64

15.43

37.48

59.53

81.57

103.62

125.66

147.71

169.76

191.80

213.85

17.64

39.68

61.73

83.78

105.82

127.87

149.91

171.96

194.01

216.05

19.84

41.89

63.93

85.98

108.03

130.07

152.12

174.17

196.21

218.26

00-16

WB91R-2 WB93R-2

Page 21

From liter to U.S. Gall.

0123456789

CONVERSION TABLE

1 ᐉ = 0.2642 U.S. Gall.

2.642

5.283

7.925

10.567

13.209

15.850

18.492

21.134

23.775

From liter to U.K. Gall.

0.264

2.906

5.548

8.189

10.831

13.473

16.115

18.756

21.398

24.040

0.528

3.170

5.812

8.454

11.095

13.737

16.379

19.020

21.662

24.304

0.793

3.434

6.076

8.718

11.359

14.001

16.643

19.285

21.926

24.568

1.057

3.698

6.340

8.982

11.624

14.265

16.907

19.549

22.190

24.832

1.321

3.963

6.604

9.246

11.888

14.529

17.171

19.813

22.455

25.096

1.585

4.227

6.869

9.510

12.152

14.795

17.435

20.077

22.719

25.361

1.849

4.491

7.133

9.774

12.416

15.058

17.700

20.341

22.983

25.625

2.113

4.755

7.397

10.039

12.680

15.322

17.964

20.605

23.247

25.889

1 ᐉ = 0.21997 U.K. Gall.

2.378

5.019

7.661

10.303

12.944

15.586

18.228

20.870

23.511

26.153

0123456789

2.200

4.399

6.599

8.799

10.998

13.198

15.398

17.598

19.797

0.220

2.420

4.619

6.819

9.019

11.281

13.418

15.618

17.818

20.017

0.440

2.640

4.839

7.039

9.239

11.438

13.638

15.838

18.037

20.237

0.660

2.860

5.059

7.259

9.459

11.658

13.858

16.058

12.257

20.457

0.880

3.080

5.279

7.479

9.679

11.878

14.078

16.278

18.477

20.677

1.100

3.300

5.499

7.969

9.899

12.098

14.298

16.498

18.697

20.897

1.320

3.520

5.719

7.919

10.119

12.318

14.518

16.718

18.917

21.117

1.540

3.740

5.939

8.139

10.339

12.528

14.738

16.938

19.137

21.337

1.760

3.950

6.159

8.359

10.559

12.758

14.958

17.158

19.357

21.557

1.980

4.179

6.379

8.579

10.778

12.978

15.178

17.378

19.577

21.777

WB91R-2 WB93R-2

00-17

Page 22

From Nm to lb.ft.

0123456789

CONVERSION TABLE

1 Nm = 0.737 lb.ft.

100

110

120

7.370

14.740

22.110

29.480

36.850

44.220

51.590

58.960

66.330

73.700

81.070

88.440

0.737

8.107

15.477

22.847

30.217

37.587

44.957

52.327

59.697

67.067

74.437

81.807

89.177

1.474

8.844

16.214

23.584

30.954

38.324

45.694

53.064

60.434

67.804

75.174

82.544

89.914

2.211

9.581

16.951

24.321

31.691

39.061

46.431

53.801

61.171

68.541

75.911

83.281

90.651

2.948

10.318

17.688

25.058

32.428

39.798

47.168

54.538

61.908

69.278

76.648

84.018

91.388

3.685

11.055

18.425

25.795

33.165

40.535

47.905

55.275

82.645

70.015

77.385

84.755

92.125

4.422

11.792

19.162

26.532

33.902

41.272

48.642

56.012

63.382

70.752

78.122

85.492

92.862

5.159

12.529

19.899

27.269

34.639

42.009

49.379

56.749

64.119

71.489

78.859

86.229

93.599

5.896

13.266

20.636

28.006

35.376

42.746

50.116

57.486

64.856

72.226

79.596

86.966

94.336

6.633

14.003

21.373

28.743

36.113

43.483

50.853

58.223

65.593

72.963

80.333

87.703

95.073

130

140

150

160

170

180

190

95.810

103.180

110.550

117.920

125.290

132.660

140.030

96.547

103.917

111.287

118.657

126.027

133.397

140.767

97.284

104.654

112.024

119.394

126.764

134.134

141.504

98.021

105.391

112.761

120.131

127.501

134.871

142.241

98.758

106.128

113.498

120.868

128.238

135.608

142.978

99.495

106.865

114.235

121.605

128.975

136.345

143.715

100.232

107.602

114.972

122.342

129.712

137.082

144.452

100.969

108.339

115.709

123.079

130.449

137.819

145.189

101.706

109.076

116.446

123.816

131.186

138.556

145.926

102.443

109.813

117.183

124.553

131.923

139.293

146.663

00-18

WB91R-2 WB93R-2

Page 23

From Nm to kgm

0123456789

CONVERSION TABLE

1 Nm = 0.102 kgm

100

110

120

1.020

2.040

3.060

4.080

5.100

6.120

7.140

8.160

9.180

10.200

11.220

12.240

0.102

1.222

2.142

3.162

4.182

5.202

6.222

7.242

8.262

9.282

10.302

11.322

12.342

0.204

1.224

2.244

3.264

4.284

5.304

6.324

7.344

8.364

9.384

10.404

11.424

12.444

0.306

1.326

2.346

3.366

4.386

5.406

6.426

7.446

8.466

9.486

10.506

11.526

12.546

0.408

1.428

2.448

3.468

4.488

5.508

6.528

7.548

8.568

9.588

10.608

11.628

12.648

0.510

1.530

2.550

3.570

4.590

5.610

6.630

7.650

8.670

9.690

10.710

11.730

12.750

0.612

1.632

2.652

3.672

4.692

5.712

6.732

7.752

8.772

9.792

10.812

11.832

12.852

0.714

1.734

2.754

3.774

4.794

5.814

6.834

7.854

8.874

9.894

10.914

11.934

12.954

0.816

1.836

2.856

3.876

4.896

5.916

6.936

7.956

8.976

9.996

11.016

12.036

13.056

0.918

1.938

2.958

3.978

4.998

6.018

7.038

8.058

9.078

10.098

11.118

12.138

13.158

130

140

150

160

170

180

190

13.260

14.280

15.300

16.320

17.340

18.360

19.380

13.362

14.382

15.402

16.422

17.442

18.462

19.482

13.464

14.484

15.504

16.524

17.544

18.564

19.584

13.566

14.586

15.606

16.626

17.646

18.666

19.686

13.668

14.688

15.708

16.728

17.748

18.768

19.788

13.770

14.790

15.810

16.830

17.850

18.870

19.890

13.872

14.892

15.912

16.932

17.952

18.972

19.992

13.974

14.994

16.014

17.034

18.054

19.074

20.094

14.076

15.096

16.116

17.136

18.156

19.176

20.196

14.178

15.198

16.218

17.238

18.258

19.278

20.298

WB91R-2 WB93R-2

00-19

Page 24

From kgm to lb.ft.

0123456789

CONVERSION TABLE

1 kgm = 7.233 lb.ft.

100

110

120

72.3

144.7

217.0

289.3

361.7

434.0

506.3

578.6

651.0

723.3

795.6

868.0

7.2

79.6

151.9

224.2

296.6

368.9

441.2

513.5

585.9

658.2

730.5

802.9

875.2

14.5

86.8

159.1

231.5

303.8

376.1

448.5

520.8

593.1

665.4

737.8

810.1

882.4

21.7

94.0

166.4

238.7

311.0

383.4

455.7

528.0

600.3

672.2

745.0

817.3

889.7

28.9

101.3

173.6

245.9

318.3

390.6

462.9

535.2

607.6

679.9

752.2

824.6

896.9

36.2

108.5

180.8

253.2

325.5

397.8

470.2

542.5

614.8

687.1

759.5

831.8

904.1

43.4

115.7

188.1

260.4

332.7

405.1

477.4

549.7

622.0

694.4

766.7

839.0

911.4

50.6

123.0

195.3

267.6

340.0

412.3

484.6

556.9

629.3

701.6

773.9

846.3

918.6

57.9

130.2

202.5

274.9

347.2

419.5

491.8

564.2

636.5

708.8

781.2

853.5

925.8

65.1

137.4

209.8

282.1

354.4

426.8

499.1

571.4

643.7

716.1

788.4

860.7

933.1

130

140

150

160

170

180

190

940.3

1012.6

1084.9

1157.3

1129.6

1301.9

1374.3

947.5

1019.9

1092.2

1164.5

1236.8

1309.2

1381.5

954.8

1027.1

1099.4

1171.7

1244.1

1316.4

1388.7

962.0

1034.3

1106.6

1179.0

1251.3

1323.6

1396.0

969.2

1041.5

1113.9

1186.2

1258.5

1330.9

1403.2

876.5

1048.8

1121.1

1193.4

1265.8

1338.1

1410.4

983.7

1056.0

1128.3

1200.7

1273.0

1345.3

1417.7

990.9

1063.2

1135.6

1207.9

1280.1

1352.6

1424.9

998.2

1070.5

1142.8

1215.1

1287.5

1359.8

1432.1

1005.4

1077.7

1150.0

1222.4

1294.7

1367.0

1439.4

00-20

WB91R-2 WB93R-2

Page 25

From bar to psi (lb/in2)

0123456789

CONVERSION TABLE

1 bar = 14.503 psi

100

110

120

145.0

290.0

435.1

580.1

725.1

870.2

1015.2

1160.2

1305.3

1450.3

1595.3

1740.4

14.5

159.5

304.6

449.6

594.6

739.6

884.7

1029.7

1174.7

1319.8

1464.8

1609.8

1754.9

29.0

174.0

319.1

464.1

609.1

754.1

899.2

1044.2

1189.2

1334.3

1479.3

1624.3

1769.4

43.5

188.5

333.6

478.6

623.6

768.6

913.7

1058.7

1203.7

1348.8

1493.8

1638.8

1783.9

58.0

203.0

348.1

493.1

638.1

783.2

928.2

1073.2

1218.2

1363.3

1508.3

1653.3

1798.4

72.5

217.5

362.6

507.6

652.6

797.7

942.7

1087.7

1232.7

1377.8

1522.8

1667.8

1812.9

87.0

232.0

377.1

522.1

667.1

812.2

957.2

1102.2

1247.2

1392.3

1537.3

1682.3

1827.4

101.5

246.5

391.6

536.6

681.6

826.7

971.7

1116.7

1261.8

1406.8

1551.8

1696.8

1841.9

116.0

261.0

406.1

551.1

696.1

841.2

986.2

1131.2

1276.3

1421.3

1566.3

1711.3

1856.4

130.5

275.6

420.6

565.6

710.6

855.7

1000.7

1145.7

1290.8

1435.8

1580.8

1725.8

1870.8

130

140

150

160

170

180

190

200

210

220

230

240

1885.4

2030.4

2175.4

2320.5

2465.5

2610.5

2755.6

2900.6

3045.6

3190.7

3335.7

3480.7

1899.9

2044.9

2189.9

2335.0

2480.0

2625.0

2770.0

2915.1

3060.1

3205.2

3350.2

3495.2

1914.4

2059.4

2204.4

2349.5

2494.5

2639.5

2784.6

2929.6

3074.6

3219.7

3364.7

3509.7

1928.9

2073.9

2218.9

2364.0

2509.0

2654.0

2799.1

2944.1

3089.1

3234.2

3379.2

3524.2

1943.4

2088.4

2233.5

2378.5

2523.5

2668.5

2813.6

2958.6

3103.6

3248.7

3393.7

3538.7

1957.9

2102.9

2248.0

2393.0

2538.0

2683.0

2828.1

2973.1

3118.1

3263.2

3408.2

3553.2

1972.4

1217.4

2262.5

2407.5

2552.5

2697.7

2842.6

2987.6

3132.6

3277.7

3422.7

3567.7

1986.9

2131.9

2277.0

2422.0

2567.0

2712.1

2857.1

3002.1

3147.1

3192.2

3437.2

3582.2

2001.4

2146.4

2291.5

2436.5

2581.5

2726.6

2871.6

3016.6

3161.6

3306.7

3451.7

3596.7

2015.9

2160.9

2306.0

2451.0

2596.0

2641.1

2886.1

3031.1

3176.1

3321.2

3466.2

3611.2

WB91R-2 WB93R-2

00-21

Page 26

CONVERSION TABLE

TEMPERATURE

Fahrenheit-Centigrade conversion; a simple way to convert a Fahrenheit temperature reading into a Centigrade temperature reading or vice versa is to enter the accompanying table in the center or boldface column of figures. These figures refer to the temperature in either Fahrenheit or Centigrade degrees. If itisdesired to convert fromFahrenheit to Centigrade degrees,consider thecenter columnas atable ofFahrenheit temperatures and read the corresponding Centigrade temperature in the column at the left. If itis desiredto convert from Centigradeto Fahrenheit degrees,consider thecenter columnas atable ofCentigrade values and read the corresponding Fahrenheit temperature on the right.

1 °C = 33.8°F

°C

–40.4 –37.2 –34.4 –31.7 –28.9

–28.3 –27.8 –27.2 –26.7 –26.1

–25.6 –25.0 –24.4 –23.9 –23.3

–22.8 –22.2 –21.7 –21.1 –20.6

–40 –35 –30 –25 –20

–19 –18 –17 –16 –15

–14 –13 –12 –11 –10

–9 –8 –7 –6 –5

°F °C °F °C °F °C °F

–40.0 –31.0 –22.0 –13.0

–4.0

–2.2 –0.4

1.4

3.2

5.0

6.8

8.6

10.4

12.2

14.0

15.8

17.6

19.4

21.2

23.0

–11.7 –11.1 –10.6 –10.0

–9.4

–8.9 –8.3 –7.8 –7.2 –6.7

–6.1 –5.6 –5.0 –4.4 –3.9

–3.3 –2.8 –2.2 –1.7 –1.1

11 12 13 14 15

16 17 18 19 20

21 22 23 24 25

26 27 28 29 30

51.8

53.6

55.4

57.2

59.0

60.8

62.6

64.4

66.2

68.0

69.8

71.6

73.4

75.2

77.0

78.8

80.6

72.4

84.2

86.0

7.8

8.3

8.9

9.4

10.0

10.6

11.1

11.7

12.2

12.8

13.3

13.9

14.4

15.0

15.6

16.1

16.7

17.2

17.8

18.3

46 47 48 49 50

51 52 53 54 55

56 57 58 59 60

61 62 63 64 65

144.8

116.6

118.4

120.2

122.0

123.8

125.6

127.4

129.2

131.0

132.8

134.6

136.4

138.2

140.0

141.8

143.6

145.4

147.2

149.0

27.2

27.8

28.3

28.9

29.4

30.0

30.6

31.1

31.7

32.2

32.8

33.3

33.9

34.4

35.0

35.6

36.1

36.7

37.2

37.8

81 82 83 84 85

86 87 88 89 90

91 92 93 94 95

96 97 98 99

100

117.8

179.6

181.4

183.2

185.0

186.8

188.6

190.4

192.2

194.0

195.8

197.6

199.4

201.2

203.0

204.8

206.6

208.4

210.2

212.0

–20.0 –19.4 –18.9 –18.3 –17.8

–17.2 –16.7 –16.1 –15.6 –15.0

–14.4 –13.9 –13.3 –12.8 –12.2

00-22

–4 –3 –2 –1

24.8

26.6

28.4

30.2

32.0

33.8

35.6

37.4

39.2

41.0

42.8

44.6

46.4

48.2

50.0

–0.6

0.0

0.6

1.1

1.7

2.2

2.8

3.3

3.9

4.4

5.0

5.6

6.1

6.7

7.2

31 32 33 34 35

36 37 38 39 40

41 42 43 44 45

87.8

89.6

91.4

93.2

95.0

96.8

98.6

100.4

102.2

104.0

105.8

107.6

109.4

111.2

113.0

18.9

19.4

20.0

20.6

21.1

21.7

22.2

22.8

23.3

23.9

24.4

25.0

25.6

26.1

26.7

66 67 68 69 70

71 72 73 74 75

76 77 78 79 80

150.8

152.6

154.4

156.2

158.0

159.8

161.6

163.4

165.2

167.0

168.8

170.6

172.4

174.2

176.0

40.6

43.3

46.1

48.9

51.7

54.4

57.2

60.0

62.7

65.6

68.3

71.1

73.9

76.7

79.4

105 110 115 120 125

130 135 140 145 150

155 160 165 170 175

221.0

230.0

239.0

248.0

257.0

266.0

275.0

284.0 2930

302.0

311.0

320.0

329.0

338.0

347.0

WB91R-2 WB93R-2

Page 27

GROUP

Page 28

40-28

PC15R-8

Page 29

STRUCTURE AND FUNCTION

Power train ................................................................ 2

Transmission (4WD).................................................. 4

Drive shafts................................................................ 9

Control valve block .................................................. 11

Front axle................................................................. 12

Rear axle ................................................................. 15

Hydraulic pump........................................................ 20

Steering unit ............................................................ 41

Hydraulic circuit ....................................................... 43

Shovel control valve ................................................ 44

Backhoe control valve ............................................. 50

CLSS ....................................................................... 57

Solenoid valve ......................................................... 71

Safety valve..............................................................72

Brake pump ..............................................................74

Shovel cylinder .........................................................75

Backhoe cylinder ......................................................76

Air-conditioning unit..................................................80

How the air-conditioning unit functions.....................81

Electrical diagram (1/6) ............................................83

Electrical diagram (2/6) ............................................85

Electrical diagram (3/6) ............................................87

Electrical diagram (4/6) ............................................89

Electrical diagram (5/6) ............................................91

Electrical diagram (6/6) ............................................93

Electrical diagram (Air conditioning).........................95

WB91R-2 WB93R-2

10-1

Page 30

STRUCTURE AND FUNCTION

POWER TRAIN

RKZ01061

DESCRIPTION

• The driving power for the engine (1) is transmitted through the flywheel to the converter (2). The converter (2) uses hydraulic oil to convert the torque transmitted by the engine (1) into driving power. The converter (2) transmits motion to the drive shaft of the transmission (3) and to the drive shaft of the hydraulic pump (4).

• The transmission (3) has two hydraulically-activated clutches that can be selected by an electricallycontrolled gearselector. It alsohas manual gear selection (four forward gears and four reverse gears).

10-2

• The driving power is transmitted from the transmission flanges (3) to the front (5) and rear (6) axles through the Cardan drive shafts (7 and 8).

• The driving power transmitted to the front (5) and rear (6) axles is reducedby thedifferentials andthen transmitted to the planetary gear through the differential shafts.

WB91R-2 WB93R-2

Page 31

STRUCTURE AND FUNCTION

POWER TRAIN

Gears

1st gear 4.280

2nd gear 2.372 33.939 2.965 50.633

3rd gear 1.236 17.685 1.544 26.367

4th gear 0.662 9.472 0.827 14.123

Transmission Differential Planetary Total Transmission Differential Planetary Total

Front axle Rear axle

61.238 5.350

2.385 6.000

Z=37

2.846 6.000

Z=75

91.362

Z=15

Z=13

1. Diesel engine

2. Convertor

3. Transmission

4. Hydraulic pump

Z=13

5. Front axle

6. Rear axle

7. Front Cardan drive shaft

8. Rear Cardan drive shaft

Z=31 Z=75

9. Rear wheels

10. Front wheels

Z=15

RKZ01031

WB91R-2 WB93R-2

10-3

Page 32

STRUCTURE AND FUNCTION

TRANSMISSION (4WD)

Diagram of the power train

TRANSMISSION (4WD)

Z=27 Z=29

4 5

Z=27

Z=29

Z=38 Z=28 Z=33

Z=19

Z=24

Z=45

Z=49

Z=36

Z=43Z=12

1. Engine

2. Convertor

3. Forward clutch

4. Transmission

5. Reverse clutch

10-4

RKZ01040

6. Hydraulic pump

7. Rear flange

8. 4WD engagement device

9. Front flange

WB91R-2 WB93R-2

Page 33

STRUCTURE AND FUNCTION

Hydraulic convertor-transmission circuit diagram

TRANSMISSION (4WD)

0.5-3.5 bar with

reverse/forward gear engaged

0.5-5 bar in neutral

Ø2

Bearing

gear

Ø3

Ø4

gear

Ø4

Forward

Ø5-Ø7

t°

11-13 bar

Ø 0.75

Hose Hose

Ø3.5

Ø1.3

Ø3.5

Ø4.5

Reverse

11-13 bar

gear

Ø3

Ø2

Bearing

11-13 bar

Air breather

Opening 23 bar

Valve open

3.45 bar

Opening

3.5-5.5 bar

0.5-9.0 bar

1. Convertor pressurization valve

2. Convertor

3. Engine

4. Oil cooler

5. Forward clutch

6. Reverse clutch

7. Max. pressure valve: calib. 23 bar

8. Spin-on filter (15

mm)

13-15.5 bar - 2200 rpm

13-14 bar - 900 rpm

9. Pump

10. Suction filter (250

11. 4WD engagement device

12. Check valve

13. Pressure control

14. 4WD engagement solenoid

15. Control valve group

mm)

4WD

Transmission oil sump

RKZ04921

WB91R-2 WB93R-2

10-5

Page 34

STRUCTURE AND FUNCTION

TRANSMISSION

b 2

a. From the oil cooler b. To the oil cooler

c. To the solenoid valve group ST1 (Port P)

d. From the solenoid valve group ST1 (Port T)

RKZ00972

1. Gear lever

2. Convertor

3. Filter

4. Oil temperature sensor

5. Suction filter

6. Y5 Reverse gears command solenoid

7. Y4 Forward gears command solenoid

8. Y2 4WD command solenoid

10-6

WB91R-2 WB93R-2

Page 35

STRUCTURE AND FUNCTION

TRANSMISSION

1. Hydraulic pump drive shaft

2. Propeller shaft

3. Reverse gears command clutch

4. Forward gears command clutch

5. Reverse gears idler shaft

6. Drive shaft

7. Flange

8. 3rd gear driven gear

9. 4th gear driven gear

Section A - A

Sezione A - A

10. 4WD drive gear

11. 1st gear driven gear

12. 4WD driven gear

13. 4WD engagement device

14. Front output shaft

15. Flange

16. 2nd gear driven gear

17. Rear output shaft

RKZ04910

WB91R-2 WB93R-2

10-7

Page 36

STRUCTURE AND FUNCTION

TRANSMISSION

Section D - D

Sezione D - D

1. Gear-shift piston

2. Spring

3. Spring

4. Ball

5. 3rd and 4th gear selecting fork

6. 1st and 2nd gear selector piston

7. 3rd and 4th gear selector piston

8. 1st and 2nd gear selecting fork

9. 4th gear selecting sensor

Section B - B

Sezione B - B

10. 3rd and 4th gear selecting fork

11. 1st and 2nd gear selecting fork

12. Suction filter (250

13. Spin-on filter (15

14. Valve

15. Spring

16. Ball

17. Spring

Section E - E

Sezione E - E

mm)

Section C - C

Sezione C - C

RKZ00991

10-8

WB91R-2 WB93R-2

Page 37

STRUCTURE AND FUNCTION

DRIVE SHAFTS

Drive shaft for forward and reverse movement

DRIVE SHAFTS

a. Port commanding reverse clutch b. Port commanding forward clutch

c. Lubrication port

Driven gear shaft

1. Reverse gear clutch (Z=29)

2. Forward gear clutch (Z=29)

3. Forwardclutchpiston

4. Reverseclutchpiston

5. Thrust ring

6. Driven shaft

RKZ00950

1. Driven gear for 2st gear (Z=43)

2. Driven gear for 1st gear (Z=49)

3. 4WD drive gear (Z=45)

4. Driven gear for 4th gear (Z=24)

WB91R-2 WB93R-2

5. Driven gear for 3rd gear (Z=33)

6. Rear output shaft

7. Thrust ring

8. Synchronizer

RKZ01010

10-9

Page 38

STRUCTURE AND FUNCTION

4WD driven shaft

DRIVE SHAFTS

a. 4WD disengagement command port 1. Front output shaft

2. 4WD driven gear (Z=36)

3. Thrust ring

4. Cylinder

5. Spring

6. Disc

RKZ01021

10-10

WB91R-2 WB93R-2

Page 39

STRUCTURE AND FUNCTION

CONTROL VALVE BLOCK

Section F - F

Sezione F - F

67 8

RKZ01000

1. Ball

2. Spring

3. Piston

4. Spring

5. Spring

6. Spring-guide pin

7. Valve

8. Spring

WB91R-2 WB93R-2

9. Valve

10. Rod

11. Spring

12. Spool return spring

13. Spool

14. Forward gear command solenoid

15. Reverse gear command solenoid

10-11

Page 40

STRUCTURE AND FUNCTION

FRONT AXLE

Differential

FRONT AXLE

1. Planetary gear

2. Ring bevel gear (Z=31)

3. Bevel gear

4. Lock nut

5. Half-axle

6. Pin

7. Differential housing

8. Spacer

9. Bearing

10. Seal

11. Flange

12. Cover

13. Lock nut

14. Bearing

15. Bevel pinion (Z=13)

16. Pin

17. Oil drain plug

RKZ00581

10-12

WB91R-2 WB93R-2

Page 41

STRUCTURE AND FUNCTION

Final reduction - joint

FRONT AXLE

1. Planetary carrier

2. Planetary (Z =29)

3. Ring gear (Z=75)

4. Ring gear carrier

5. Wheel hub

6. Seal

7. Pin

8. Shim

9. Protection

10. Bushing

11. Seal

12. Axle body

13 14 15

13. Bearing

14. Joint

15. Pin

16. Protection

17. Seal

18. Bearing

19. Snap ring

20. Steady pin

21. Stud bolt

22. Plug

23. Sun gear (Z=15)

24. Snap ring

RKZ00611

WB91R-2 WB93R-2

10-13

Page 42

STRUCTURE AND FUNCTION

Steering cylinder

FRONT AXLE

Section A - A

Sezione A - A

1. Steering cylinder

2. Oil refilling plug

3. Oil drain plug

4. Nut

5. Adjustment screw

6. Nut

7. Bushing

Section B - B

Sezione B - B

Detail C

Particolare C

RKZ00591

a Port - From the steering unit (L Port) b Port - From the steering unit (R Port)

10-14

WB91R-2 WB93R-2

Page 43

STRUCTURE AND FUNCTION

REAR AXLE

Differential

REAR AXLE

3456

8 9

1. Bearing

2. Planetary gear

3. Bevel gear

4. Ring bevel gear (Z=37)

5. Differential housing

6. Lock nut

7. Half-axle

8. Pin

WB91R-2 WB93R-2

RKZ04970

9. Bearing

10. Nut

11. Seal

12. Flange

13. Spacer

14. Bevel pinion (Z=13)

15. Differential housing

10-15

Page 44

STRUCTURE AND FUNCTION

Final reduction

REAR AXLE

5 6

1. Planetary gear carrier

2. Stud bolt

3. Wheel hub

4. Planetary gears (Z=28)

5. Ring bevel gear carrier

6. Bearing

7. Seal

8. Joint

9. Half-axle

10-16

RKZ04980

10. Planetary gear (Z=15)

11. Bushing

12. Snap ring

13. Ring gear (Z=75)

14. Oil plug

15. Steady pin

16. Pin

WB91R-2 WB93R-2

Page 45

STRUCTURE AND FUNCTION

Brakes

REAR AXLE

Detail B

Particolare B

Section A - A

Sezione A - A

RKZ04990

1. Bushing

2. Parking brake control rod

3. Bleeder valve

4. Parking brake lever

5. Parking brake control cam

WB91R-2 WB93R-2

6. Brake disk

7. Piston

8. Spring

9. Pressure disk

10. Intermediate disk

10-17

Page 46

STRUCTURE AND FUNCTION

Differential locking

REAR AXLE

a. From the solenoid valve block ST1 (Port 2)

1. Sleeve

2. Pin

3. Control rod

4. Spacer

5. Fork

6. Piston

7. Cover

8. Snap ring

10-18

RKZ05000

WB91R-2 WB93R-2

Page 47

PAGE INTENTIONALLY

LEFT BLANK

Page 48

STRUCTURE AND FUNCTION

HYDRAULIC PUMP

1. Delivery variation group

2. Y1 solenoid valve working mode

3. Delivery control valve

10-20

RKZ04930

a. Port L1 - To the intake flange (Spool Port)

b. Port B - To the shovel control valve (Port P)

c. Port X2 - From the shovel control valve

(Port LS) d. Port L - To the hydraulic oil tank

e. Port S - To the hydraulic oil tank

WB91R-2 WB93R-2

Page 49

STRUCTURE AND FUNCTION

HYDRAULIC PUMP

Section A - A

Sezione A - A

1. Seal

2. Bearing

3. Central spring

4. Bearing

5. Control rod

6. Swash plate

Section B - B

Sezione B - B

10. Positioning piston

11. Piston

12. Guide shoe

7. Positioning piston

8. Spring

9. Cylinder block

RKZ00380

WB91R-2 WB93R-2

10-21

Page 50

STRUCTURE AND FUNCTION

HYDRAULIC PUMP

Section C - C

Sezione C - C

POWER GOVERNOR

1. Spring

2. Piston rod

3. Bushing

4. Initial adjustment spring

5. Pressure cut calibration spring

6. Pressure cut calibration screw

7. Initial adjustment calibration screw

PC VALVE

8. Spool

9. Spring (internal)

10. Spring (external)

10-22

Section D - D

Sezione D - D

LS VALVE

11. External spring

12. Internal spring

13. Throttles

14. Throttles

15. Spool

RKZ00642

WB91R-2 WB93R-2

Page 51

STRUCTURE AND FUNCTION

FUNCTION

• The rotation and torque transmitted to the pump shaft is converted into hydraulic energy and pressurized oil is deliveredaccording tothe loadrequirements.

• The amount of oil delivered can be modified by changing the angle of the swash plate.

HYDRAULIC PUMP

RKZ01120

STRUCTURE

• The cylinder block (6) is supported and connected to the shaft (1) by the spline a and the shaft (1) is supported by the front and rear bearings.

• The tip of the piston (6) is ball-shaped. The shoe (4) is caulked to itto form oneunit in sucha waythat the piston (5) and theshoe (4) togetherform a spherical bearing.

• The swash plate (3) has a flat surface A and the shoe (4) remainspressed against this surface while sliding in a circular movement. The swash plate brings highly pressurized oil onto the cylindrical surface B fashionedin thepump body (2), whichmeans thatthe swash plate (3) slides ona hydrostatically-supported bearing.

WB91R-2 WB93R-2

• The pistons (5) perform their relative movements in an axial direction, inside cylindrical chambers fashioned in the cylinder block (6).

• The oil is brought up to pressure in the chambers of the cylinder block (6) by the rotatory movement of the block itself. The areas of pressure and suction are determined by the swash plate (7). Thesurfaceoftheswashplateissodesignedthat the oil pressure always remains within acceptable limits. The oil in each chamber is drawn in and discharged through holes in the valve plate (7).

10-23

Page 52

STRUCTURE AND FUNCTION

OPERATION

1. Pump operation

1 - The cylinder block (7) rotates together with the

shaft (1) and the shoe (4) slides on the flat surface A. The swash plate (3) moves along the cylindrical surface B. The angle tween the center line of the shaft (1) and the center line X of the swash plate (3) changes, thus modifying the axial position of the pistons in relation to the cylinder block. The angle

= is known as theswash plateangle.

= formed be-

HYDRAULIC PUMP

2 - When the center line X of the swash plate (3)

maintains the angle line of the shaft (1), and hence also of the cylinder block (6),the flatsurface Aacts as a cam for the shoe(4). Asthe piston(5) rotatesand slides inside thecylinder block (6), it therefore creates a difference between the volumes C and D which provokes intake and discharge of the oil in quantities equal to the difference between the volumes (D – C=delivery). In otherwords, as the cylinderblock (6) rotates, chamber D loses volume while the volume of chamber C is increased, thus provoking an intake of oil. (The figure indicates the state of the pump when the intake of chamber D and the delivery of chamber C have been completed).

3 - When the center line X of the swash plate (3)

and the center line of the cylinder block (6) are perfectly aligned (the swash plate angle the difference between the volumes C and D within the cylinder block (6) becomes 0 and the pump does not take in or deliver any oil. (In practice the swash plate angle comes=0)

= in relation to the center

==0),

= never be-



 =0

RKZ01100

4 - In other words, pump delivery is directly pro-

portional to the swash plate angle

10-24

RKZ01110

WB91R-2 WB93R-2

Page 53

STRUCTURE AND FUNCTION

2. Control of Delivery

HYDRAULIC PUMP

1 - As the swash plate angle = grows larger, the

difference between volumes C and D increases, and the delivery Q also increases. The swash plate angle is modified by servo-pistons (8) and (9).

2 - The servo-piston (8) moves in a reciprocating

linear motion ( ) caused by pressure signals from the PC and LS valves. The linear movement is transmitted to the swash plate (3), which is supported by the cylindrical surface of the cradle (2). The swash plate therefore has a semi-circular reciprocating movement ( ).

3 - The surfaces of the servo-pistons receiving the

pressures PP and LS are dissimilar. The delivery pressure PP of the main pump is always passed into the smaller (upper) pressure chamber, whereas the pressure PEN coming from theLS valve is passedinto the larger (lower) pressure chamber. The movement of the servo-piston is governed by the relationship between pressures PP and PEN, as well by the proportions between the surfaces (larger and smaller) of the servo-piston.



RKZ01130

WB91R-2 WB93R-2

10-25

Page 54

STRUCTURE AND FUNCTION

PC VALVE, LS VALVE, SERVO PISTON

HYDRAULIC PUMP

Control valve

SERVO-PISTON

1. Spring

2. Servo-piston

3. Servo-piston

LS VALVE

4. Piston

5. Spring

To the actuator

PC VALVE

6. Servo-piston

7. Spring

RKZ01141

10-26

WB91R-2 WB93R-2

Page 55

STRUCTURE AND FUNCTION

LS VALVE

FUNCTION

• The LS valve controls the pump delivery according

to the stroke of the control valve level, i.e., in function of the delivery demands madeby the actuators.

• The LS valve detects the actuator’s delivery needs

by means of thedifferential pressure between the pump delivery pressure PP and the pressure PLS coming from the control valve. This reading permits control of the main pump delivery Q. (PP, PLS and pressure, the Load Sensing pressure, and the difference in pressure between these two values).

• In other words, the LS valve detects the pressure

difference oil flow through the surface freed by the control valve spool, and controls the pump delivery Q so as to keep the pressure drop constant. It can therefore be assumed that the pump delivery is proportional to the demands made known by the control valve.

,PLS are, respectively, the pump

,PLS generated by the passage of the

,PLS existing

HYDRAULIC PUMP

WB91R-2 WB93R-2

10-27

Page 56

STRUCTURE AND FUNCTION

OPERATION

1. When the control valve is in a «NEUTRAL» position

HYDRAULIC PUMP

To the actuator

Min

Max

• The pressure PLS of the LScoming from the control valve outlet passes into chamber a ofthespringof the LS valve. The pressure PP of the pump passes into chamber b of the opposite side.

• The piston rod movement (4) is determined by the combination of the force generated by the pressure PLS, the force of the spring (6) and the force generated on the side opposite the piston rod by the pressure PP.

• Before the engine is started the servo-piston (3) is pushed to the right by the spring (1) (corresponding to the maximum angle of the swash plate).

• If all the control valve spools are in their «NEUTRAL» position when the engine is started, the pressure PLS of the LS will remain at 6 cause no oil is flowing through the control valve. AtthesametimethepumppressurePP increases and is maintained at a value of about 27 bar.

±2barbe-

Control valve

• For this reason the piston (4) is thrust to the right ( ) and a passage is formed between the delivery lines c and d. This opening enables the pump pressure PP to enter chamber X of the servo-piston (3).

• Although the pump pressure PP is always passed into chamber Y of the servo-piston (2), since the force exertedby that pressure onpiston (3) exceeds the force exerted on piston (2), the servo-piston (1) moves to the right ( ), i.e. towards the side of the minimum angle of the swash plate.

RKZ01151

10-28

WB91R-2 WB93R-2

Page 57

STRUCTURE AND FUNCTION

2. When a control valve lever is activated

HYDRAULIC PUMP

To the actuator

Min

Max

• When the control valve lever is moved out of its

NEUTRAL position, the opening f is determined, allowing an LS signal to be generated.

• Until the exerted by the spring (6) on the spool (4),the system will remain stable. When the opening f is such as to provoke a reduction in form a passage between delivery lines d and e.The chamber X loses pressure and the servo-piston causes the swash plate to move towards maximum displacement.

,PLS generates a force less thanthe force

,PLS, the spool (4)moves to the left( ) to

Control valve

• Equilibrium is re-established in the system when the pressure ference in force exerted by the spring (6), and the passage between delivery lines c and d is reopened.

,PLS generates on the spool (4) the dif-

RKZ01161

WB91R-2 WB93R-2

10-29

Page 58

STRUCTURE AND FUNCTION

3. When the control valve opening is at its maximum (lever at the end of its stroke)

HYDRAULIC PUMP

Min

Max

• When thecontrol lever is moved tofull stroke, in other words, when the spool opening reaches its maximum, the difference between the pump pressure PP and the LS pressure PLS becomes smaller (differential pressure

• The LSpressure PLSintroduced intothe chamber a of the LS valve becomes about the same as the pump pressurePP andthe piston(4) ismoved to the left ( ) by the combined forces generated by the pressure PLS and the spring (6). The piston movement closes the delivery line c and forms a passage between lines d and e.

,PLS).

To the actuator

Control valve

• The pressurized oil present in the chamber X of the servo-cylinder (3) flows through the lines d and e and reaches the pump drainage chamber, so that the pressure in chamber X of the servo-cylinder (1) becomes equal to the drainage pressure.

• The servo-piston(3) is thus moved to the right ( ) by swash plate movement due tothe pressure PPin the chamber Y of the servo-cylinder (2). In other words, it is drawn in the direction of the increase in angle of the swash plate.

RKZ01161

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WB91R-2 WB93R-2

Page 59

STRUCTURE AND FUNCTION

4. When the spool makes very small movements (fine-control)

To the actuator

HYDRAULIC PUMP

Min

Max

• When the control valve lever moves in very small increments towards the «NEUTRAL» position, i.e. when thecontrol valve opening f diminishes, the differential pressure sure PP and the LS pressure PLS increases.

• If the differential pressure spool (4) a differencein forcethat exceeds theforce exerted by the spring (6), the spool moves to the right ( ) and a passage is formed between the delivery lines c and d. The pressure PP is introduced into the chamber X and the swash plate moves towards its minimum angle.

• When the control valve lever performs small movements towards the position of maximum opening, i.e. when the opening f of the control valve increases, the differential pressure

,PLS between the pump pres-

,PLS generates on the

,PLS diminishes.

Control valve

• If the differential pressure spool (4) a force differencethat does not exceedthe force exerted by the spring (6), the spool (4) moves to the left ( ) and a passage is formed between the delivery lines d and e. The chamberX losespressure and theservo-piston provokes a movement of the swash plate towards maximum displacement.

• Equilibrium is re-established in the system when the pressure ference inforce exerted by the spring (6),and hence the passage between delivery lines c and d is also re-opened.

,PLS generates on the spool (4) the dif-

RKZ01171

,PLS generates on the

WB91R-2 WB93R-2

10-31

Page 60

STRUCTURE AND FUNCTION

5. When pump flow matches the demands of the control valve

To the actuator

HYDRAULIC PUMP

Hold

• Let A1 be the surface of the servo-piston (3), A2 the surface of the servo-piston (2), PEN the pressure acting on the piston (1) and PP the pressure acting onthepistonside(2).

When pump delivery reaches the quantity demanded by the control valve, the pump pressure PP in chamber b of the LS valve is in equilibrium with the combined forces of the LS pressure PLS in chamber a, and the force exerted by the spring (6). Once equilibrium has been reached the piston (4) stops in the central position.

• In this condition the passage from chamber c to chamber d remains only slightly open in order to maintain pressure in chamber d.

Control valve

PEN

A flow of oil is introduced into the servo-cylinder (3) at a pressure that balances the force generated by the pump pressure PP in the cylinder (2). (PEN x A1=PP x A2).

• The stability of the equilibrium is guaranteed by a

flow stabilized by the throttle g.

• The force of the spring (6) is regulatedso that the piston (4) is in equilibrium when

PP – PLS =

• In practice, the pump flow is made proportional to the sectionof the opening of the controlvalve, which maintains the differential pressure

,PLS =18 bar.

RKZ01181

,PLS = 18 bar.

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WB91R-2 WB93R-2

Page 61

STRUCTURE AND FUNCTION

PC VALVE

FUNCTION

• The PC valve performs an approximate power

check, and ensures that the hydraulic horse-power absorbed bythe pump does not exceed the horsepower delivered by the endothermal engine. This is achieved by limiting the pump delivery Q in function of the delivery pressure PP,eveniftheLS valve requests an increase in delivery Q due to the larger sectionfreed by the controlvalve spool, in the presence of high pressure pump delivery.

• In other words, when during operation the delivery

Q increases and the delivery pressure PP also in- creases simultaneously, the PC valve reduces the pump delivery Q. When the delivery pressure PP decreases, the PC valve increases the pump flow.

• The relationships between the pump delivery pres-

sure PP and the delivery Q are shown in the diagram.

HYDRAULIC PUMP

Pump discharge amount Q

Pump discharge pressure

RKP01181

WB91R-2 WB93R-2

10-33

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STRUCTURE AND FUNCTION

OPERATION

1. When the load on the actuators is heavy (high pump delivery pressure)

∆ p

PPC

HYDRAULIC PUMP

PPC

Min

Control valve

Max

To the actuator

• When a higher delivery is required, the LS valve re-

ceives a signal from the control valve to bring the pump up to maximum displacement. When the swash plate moves it also moves the bushing (2) joined to it (by the pin (1)), which releases the spring (3).

• As the pressure of the actuators increases, pres-

sure also increases in the delivery line c. When the calibrated setting of thespring (3) is reached, thepiston rod (4) is thrust to the left ( ) and the passage between chamber b and the pump drainage chamber a is opened.

RKZ01191

• The opening of the passagebetween the chambers b and a generates a flowof oil and hence, dueto the calibrated hole (6), a chambers f andg atthe sidesopposite the spool(5). (

,P=PP– PPC)

• When the value of PP exceeds the value of the spring loading (7) the spool (5) moves to the right ( ) opening the passage between the delivery lines d and e and sending the pumppressure PPtowards the servo-cylinder (8).

• The pressure PP introduced into chamber X of the cylinder (8) pushes it towards the minimum angle of theswashplate( ).

,P is generated between

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WB91R-2 WB93R-2

Page 63

STRUCTURE AND FUNCTION

2. When equilibrium has been reached

HYDRAULIC PUMP

∆ p

PPC

PEN

To the actuator

Hold

Control valve

• When the piston (8) is pushed to the left ( ) the bushing (2) is also moved. The oil flow between the chambers b and a is reduced and the PPC pressure tends to approach the PP pressure value. The

,P decreasesand the spool (5) is pushed to the

left ( ) by the force of the spring (7).

• Equilibrium is reached whenthe forcegenerated by the PP pressure, the force generated by the PPC pressure, and the force of the spring (7) are all balanced. (The force generated by PP = the force generated by the PPC + the spring force (7)).

WB91R-2 WB93R-2

• In this condition the passage from chamber d# to

chamber e remains only slightly open in order to maintain pressure in chamber e. A flow of oil is introduced into the cylinder (8) at a pressure that balances the force generated by the pumppressure PP acting on the cylinder (9). (PENxA1=PPxA2)

• The stability of this equilibrium is generated by a continuous stabilized flow from the throttle (10).

RKZ01201

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STRUCTURE AND FUNCTION

3. When the load on the actuators decreases (pump delivery pressure drops)

HYDRAULIC PUMP

PPC

PEN

To the actuator

Control valve

Hold

• When the load on the actuators diminishes and the

pump delivery pressure PP drops, the PPC.pressure also drops.

• The reduction in the PPC causes the spool (4) to move and the passage between chambers b, d and a is closed. The PPCpressure and the PP pressure ofthe pump are equalised due to the interruption of the oil flow through the calibrated hole (6) and hence the becomes zero (

• The spring (7) pushes the spool (5) to the left ( ) closing the passage between the chambers d and e and opening the passage between chambers e and g.

,P=PP– PPC=0).

• The pressurized oil present in chamber X of the ser- vo-cylinder (8) passes through chambers e and g and reaches the pump drainage chamber, so that the pressure in chamber X of the servo-cylinder (7) becomes equal to the drainage pressure.

• Therefore the servo-piston (7) is caused to move by the PP pressure in chamber Y of the servo-cylinder (9), i.e. in thedirection of the increase in theangle of the swash plate.

RKZ01211

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WB91R-2 WB93R-2

Page 65

STRUCTURE AND FUNCTION

4. The function of the spring

HYDRAULIC PUMP

To the actuator

Control valve

• The loading on the springs (3) and (11) of the PC

valve changes in proportion to the angle of inclination of the pump swash plate.

• The compression of the spring (3) varies with the movements of the servo-piston (8).

• Whenthepiston(8)movestotheleft( ),the spring (3) is compressed. If the piston (8) moves even further to the left ( ), the spring (11) comes into action to increase the loading. In other words, the overall loading of the springs is varied by the piston (8), whicheither compresses or releases them.

• The pump absorption torque curve, which indicates the relationship between the pump delivery pressure PP and the delivery Q, is a broken line (as illustrated in the diagram).

WB91R-2 WB93R-2

RKZ01221

Spring(3)+ spring(11

Spring(3

Pump discharge amount Q

Pump discharge pressure

)

RKZ01241

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Page 66

STRUCTURE AND FUNCTION

• The position in which the piston (8) stops, i.e. the pump absorption torque, is determined by the positionin which thePPC pressure applied tothe spool (4) is balanced by the force exerted by the springs (3) and (11).

• In practice, as the pump delivery pressure PP in- creases, the delivery Q decreases, and as the pressure PP diminishes the pump delivery Q increases.

HYDRAULIC PUMP

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WB91R-2 WB93R-2

Page 67

STRUCTURE AND FUNCTION

WORKING MODE SOLENOID VALVE

FUNCTION

• Calibration of the pump absorption torque is nor-

mally performed for the working mode E. When the solenoid valve of the working mode is commutated the absorbed power of the pump is increased, as indicated by the working mode curve.

OPERATION

HYDRAULIC PUMP

Working mode P

Working mode E

Pump discharge amount Q

Pump discharge pressure Pp

RKZ01251

1. WORKING MODE E

12V DC

∆ P1

• During normal operation (Working mode E), the PC

valve intervenes when a the loading on the spring (4).

,P1 is generated equal to

WB91R-2 WB93R-2

RKZ04940

• The

,P1 is generated by the calibrated hole (3) in

the spool of the PC valve (2) when, at a determined pump delivery pressure P1, the valve (1) puts the delivery linea into discharge,thus generating aflow F1 in the delivery line a.

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Page 68

STRUCTURE AND FUNCTION

2. WORKING MODE P

HYDRAULIC PUMP

∆ P2

12V DC

• When the solenoid valve (6) is commutated (Working Mode P) the pressurized oil coming from the pump changes its route and passes through the throttle (5),which has a larger diameter than the calibrated hole (3).

• Because the throttle (5) has a larger diameter, the

,P2 generated is less than is needed to overcome

the force generated by the spring (4). The spool of the PCvalve (2) is thereforepushed to the left( ) by the force of the spring (4).

• This shift obliges the pump to increase displacement and hence the delivery (See «PC VALVE: 3. When the load on the actuators decreases» third paragraph).

RKZ04950

• The increase in flow causes an increment of the

,P2 which, when the loading value of the spring is

reached, allows the spool to shift to the right ( ).

• The pump starts to work in normal fashion once again, and all the valves recommence normal functioning.

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WB91R-2 WB93R-2

Page 69

STRUCTURE AND FUNCTION

STEERING UNIT

b d

240 bar 240 bar

175

bar

a. Port LS - From the shovel control valve

(Port DLS) b. Port T - To the hydraulic oil tank

c. Port L - To the steering cylinder (Port a)

d. Port R - To the steering cylinder (Port b) e. Port P - From theshovel control valve (Port D)

RKZ00831

TECHNICAL DATA

Steering unit type: LAGCSDS160P

Displacement: 160 cc/rev.

OPERATION

• The steering unit is composed ofa control valve and a rotating oil dispenser, and is of the hydrostatic type.

• When the steering wheelis turned, the control valve sends oil from the pump P2 (by means of the rotating oil dispenser) to one of the sides of the steering cylinder. The rotating dispenser ensures that the volume of oil supplied to thecylinder isproportionate to the angle of rotation of the steering wheel.

• In the event of malfunction, the oil dispenser will function automatically as a hand-pump, thus guaranteeing emergency steering.

WB91R-2 WB93R-2

10-41

Page 70

PAGE INTENTIONALLY

LEFT BLANK

Page 71

STRUCTURE AND FUNCTION

HYDRA ULIC CIRCUIT

HYDRAULIC CIRCUIT

P2T1

bar

-5

WB91R-2:185 bar

WB93R-2:200 bar

-5

LST

LS1

Hammer

A1B1

160 bar

Arm

A2B2

230 bar

Boom swing

ABTTAT

230

bar

R.H. outrigger

A4B4A3B3

L.H. outrigger Bucket

A5B5

ABT

230 bar

Boom

A6B6

l/mn

ABTT

300

230

bar

Jig arm

A8B8A7B7

12V DC

240

bar

175

bar

LS D

DLS

5 bar

Arm

B1 A1

Bucket

B2 A2

TBAT TBAT

170

230

bar

Additional equipment

B3 A3

230

bar

WB91R-2 WB93R-2

L1 L

RKZ05031

10-43

Page 72

STRUCTURE AND FUNCTION

SHOVEL CONTROL VALVE

2SPOOL

SHOVEL CONTROL VALVE

Section A - A

Sezione A - A

a. Port D - To the hydraulic steering unit (Port P)

b. Port A2 - To the bucket cylinders (Head side) c. Port A1 - To the shovel-raising cylinders

(Base side)

d. Port LS - To the pump (Port X2)

e. Port T - To the hydraulic oil tank f. Port P - From the pump (Port B)

g. Port B1 - To the shovel-raising cylinders

(Head side)

h. Port B2 - To the bucket cylinders (Base side) i. Port DLS - To the hydraulic steering unit

(Port LS)

Section B - B

SezioneB-B

1. Plug

2. Plug

3. Ball

4. Spring

5. Priority valve piston rod

6. Priority valve spring

4 5

RKZ01082

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WB91R-2 WB93R-2

Page 73

STRUCTURE AND FUNCTION

SHOVEL CONTROL VALVE

Section C - C

Sezione C - C

Section D - D

Sezione D - D

1. Plug

2. Raising command spool

3. Spool return spring

4. Compensator

5. Antishock/anticavitation valve

6. Bucket dump command spool

7. Spring

8. Check valve

Section E - E

Sezione E - E

RKZ00660

WB91R-2 WB93R-2

10-45

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STRUCTURE AND FUNCTION

3 SPOOL

SHOVEL CONTROL VALVE

a. Port D - To the hydraulic steering unit (Port P) b. Port A3 - To the auxiliary equipment (Left side)

c. Port A2 - To the bucket cylinders (Head side)

d. Port A1 - To the shovel-raising cylinders

(Base side) e. Port LS - To the pump (Port X2)

f. Port T - To the hydraulic oil tank

g. Port P - From the pump (Port B) h. Port B1 - To the shovel-raising cylinders

(Head side)

i. Port B2 - To the bucket cylinders (Base side)

l. Port B3 - To the auxiliary equipment

(Right side) m. Port DLS - To the hydraulic steering unit

(Port LS)

Section A - A

Sezione A - A

Section B - B

Sezione B - B

1. Plug

2. Plug

3. Ball

4. Spring

5. Priority valve piston rod

6. Priority valve spring

7. Plug

4 5

RKZ01072

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WB91R-2 WB93R-2

Page 75

STRUCTURE AND FUNCTION

SHOVEL CONTROL VALVE

Section C - C

Sezione C - C

Section D - D

Sezione D - D

1. Plug

2. Raising command spool

3. Spool return spring

4. Spring

5. Ball

6. Ball

7. Compensator

8. Antishock/anticavitation valve

Section F - F

Sezione F - F

Section E - E

Sezione E - E

9. Bucket dump command spool

10. Spool return spring

11. Optional equipment command spool

12. EV1 Opened bucket 4 in 1 solenoid valve

13. EV2 Closed bucket 4 in 1 solenoid valve

14. Spring

15. Check valve

RKZ00691

WB91R-2 WB93R-2

10-47

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STRUCTURE AND FUNCTION

3 SPOOL (WITH RETURN TO DIG)

SHOVEL CONTROL VALVE

a. Port D - To the hydraulic steering unit (Port P)

b. Port A3 - To the auxiliary equipment (Left side)

c. Port A2 - To the bucket cylinders (Head side) d. Port A1 - To the shovel-raising cylinders

(Base side)

e. Port LS - To the pump (Port X2)

f. Port T - To the hydraulic oil tank g. Port P - From the pump (Port B)

h. Port B1 - To the shovel-raising cylinders

(Head side)

i. Port B2 - To the bucket cylinders (Base side) l. Port B3 - To the auxiliary equipment

(Right side)

m. Port DLS - To the hydraulic steering unit

(Port LS)

Section A - A

Sezione A - A

4 5

Section B - B

Sezione B - B

1. Plug

2. Plug

3. Ball

4. Spring

5. Priority valve piston rod

6. Priority valve spring

7. Plug

RKZ01092

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WB91R-2 WB93R-2

Page 77

STRUCTURE AND FUNCTION

SHOVEL CONTROL VALVE

Section C - C

Sezione C - C

1. Plug

2. Raising command spool

3. Spool return spring

4. Spring

5. Ball

6. Ball

7. Compensator

Section D - D

Sezione D - D

Section E - E

Sezione E - E

Section F - F

Sezione F - F

8. Antishock/anticavitation valve

9. Bucket dump command spool

10. Spool return spring

11. Coil

12. Optional equipment command spool

13. Spring

14. Check valve

RKZ00940

WB91R-2 WB93R-2

10-49

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STRUCTURE AND FUNCTION

BACKHOE CONTROL VALVE

6 SPOOL

BACKHOE CONTROL VALVE

Section A - A

Sezione A - A

a. Port P - From the pump (Port B)

b. Port T - To the hydraulic oil tank

c. Port B1 - To the arm cylinder (Base side) d. Port B2 - To the arm LH swing cylinder

(Base side)

e. Port B3 - To the RH outrigger cylinder

(Base side)

f. Port B4 - To the LH outrigger cylinder

(Base side) g. Port B5 - To the bucket cylinder (Base side)

h. Port B6 - To the boom cylinder (Head side)

i. Port C - To the backhoe backframe

lock cylinders

Section B - B

Sezione B - B

l. Port A6 - To the boom cylinder (Base side)

m. Port A5 - To the bucket cylinder (Head side)

n. Port A4 - To the LH outrigger cylinder

(Head side)

o. Port A3 - To the RH outrigger cylinder

(Head side)

p. Port A2 - To the RH boom swing cylinder

(Base side)

q. Port A1 - To the arm cylinder (Head side) r. Port T1 - To the hydraulic oil tank

s. Port LS - To the pump (Port X2)

RKZ00230

10-50

WB91R-2 WB93R-2

Page 79

STRUCTURE AND FUNCTION

BACKHOE CONTROL VALVE

Section C - C

Sezione C - C

Section D - D

Sezione D - D

Section E - E

Sezione E - E

Section F - F

Sezione F - F

1. Ball

2. Backhoe backframe lock solenoid valve

3. Antishock/anticavitation valve

4. Boom command spool

5. Spool return spring

6. Compensator

7. Bucket command spool

Section G - G

Sezione G - G

RKZ00760

8. Anticavitation valve

9. Plug

10. Outrigger command spool

11. Boom swing command spool

12. Arm command spool

13. Spring

14. Check valve

WB91R-2 WB93R-2

10-51

Page 80

STRUCTURE AND FUNCTION

BACKHOE CONTROL VALVE

1. Valve

2. Spring

3. Plug

Section H - H

Sezione H - H

Section L - L

Sezione L - L

4. Pressure cut-out valve

5. Unloading valve

RKZ00790

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WB91R-2 WB93R-2

Page 81

PAGE INTENTIONALLY

LEFT BLANK

Page 82

STRUCTURE AND FUNCTION

7 SPOOL For jig arm

BACKHOE CONTROL VALVE

For side digging boom

For hammer

RKZ00240

RKZ00250

a. Port B7 - To the jig arm cylinder (Base side)

b. Port A7 - To the jig arm cylinder (Head side)

c. Port B7 - To the side digging boom cylinder

(Base side)

10-54

RKZ00260

d. Port A7 - To the side digging boom cylinder

(Head side)

e. Port B7 - To the hydraulic hammer (Left side)

WB91R-2 WB93R-2

Page 83

STRUCTURE AND FUNCTION

BACKHOE CONTROL VALVE

Section A - A

Sezione A - A

Section B - B

Sezione B - B

1. Anticavitation valve

2. Jig arm command spool

3. Spool return spring

4. Plug

WB91R-2 WB93R-2

Section C - C

Sezione C - C

5. Compensator

6. Anti-shock/anticavitation valve

7. Side digging boom command spool

8. Hammer command spool

RKZ00960

10-55

Page 84

STRUCTURE AND FUNCTION

8 SPOOL For hammer and jig arm

a b

BACKHOE CONTROL VALVE

For side digging boom and jig arm

a. Port B7 - To the hydraulic hammer (L.H. side)

b. Port B8 - To the jig arm cylinder (Base side) c. Port A8 - To the jig arm cylinder (Head side)

d. Port B7 - To the side digging boom cylinder (Base side)

e. Port A7 - To the side digging boom cylinder (Head side)

RKZ00270

RKZ00280

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WB91R-2 WB93R-2

Page 85

STRUCTURE AND FUNCTION

CLSS (Closed Center Load Sensing System)

CLSS

(Closed Center Load Sensing System)

1. DESCRIPTION

CHARACTERISTICS

The term CLSS means Closed Center Load Sensing System, which has the following characteristics:

a) High precision control that is independent of the load applied to the movement; b) High precision control of digging action even during delicate manoeuvres;

c) Ability to perform complex operations, guaranteed by control of oil flow in function of the aperture surfaces of the

shuttles;

d) Energy savings guaranteed by control of pump delivery.

STRUCTURE

• The CLSS system includes the variable flow pump, the control valve and the working equipment.

• The pump includes the main pump, the PC valve and the LS valve.

Attachment

PLS

PC Valve

LS Valve

Piston

Control valve

Piston

RKZ01711

WB91R-2 WB93R-2

10-57

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STRUCTURE AND FUNCTION

CLSS (Closed Center Load Sensing System)

2. OPERATING PRINCIPLES

1. Control of the angle of the pumping plate.

• The angle of the swash plate(and hence the pump delivery) is controlledin such a way thatthe differential pressure

,PLS betweenthe delivery pressure PPof the pump and thepressure PLS at the outletof the control valvetowards

the actuatoris maintained at aconstant value. ( actuator).

• If the differential pressure

increases (delivery increasing). If the differential pressure

,PLS becomes lower than the set pressure of the LS valve, the angle of the swash plate

,PLS increases, the angle of the swash plate decreases.

★ For details about this movement, see the description of the «HYDRAULIC PUMP».

Control valve

,PLS=pump deliverypressure PP – pressure PLS of deliveryto the

Attachment

Piston

Pump delivery

Piston

PUMP

PC Valve

High pressure

LS Valve

High pressure

10-58

RKZ01721

WB91R-2 WB93R-2

Page 87

STRUCTURE AND FUNCTION

CLSS (Closed Center Load Sensing System)

2. Pressure compensation control

• The pressure compensation valves are installed downstream from the control valve in order to balance the differential pressure between the loads. When two or more movements (cylinders) are activated simultaneously, the pressure differences delivery at the control valve inlet and outlets of the control valve are compensated by these valves. We obtain the distribution of the pump flow in proportion to the areas of passage S1 and S2 of each valve.

,P between the

Pressure compensation valve

⌬

Load

Actuator

Pressure compensation valve

Load

Actuator

⌬

WB91R-2 WB93R-2

PUMP

RKZ01731

10-59

Page 88

STRUCTURE AND FUNCTION

CLSS (Closed Center Load Sensing System)

3. UNLOADING VALVE FUNCTION

1. When the control valve is in «NEUTRAL» position, the flow Q of the pump (due to the swash plate being in the minimum angle position) is sent to the control valve. In these conditions, the pump delivery pressure PP is regulated to 27 bar by the spring (2) inside the valve. (PP=PLS + spring load with PLS=6 bar)

OPERATION

When the control valve is in «NEUTRAL» position

• On the two surfaces of the shuttle (1), the pump pressure PP acts on the right-hand side, while the LS signal with pressure PLS acts on the left-hand side.

• Because a LS signal is generated with a pressure PLS 6

±2bar,whenthecontrolvalveisin«NEU-

TRAL» position, the pump delivery pressure PP is regulated by the combination of the pressure provided by the spring and by the LS pressure PLS.

• While the pumpdelivery pressure PPincreases until it compensates for the loading on the spring (2) and for the LS pressure 27 bar, the shuttle (1) moves to the left ( ) and the PP circuit is put intocommunication with the tank circuit T.

• This system ensures that the pump delivery pressure

PP stays regulated at 27 bar.

RKZ01740

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WB91R-2 WB93R-2

Page 89

STRUCTURE AND FUNCTION

2. If, during the precision regulations of the control valve, the request for oil flow to the actuators in equal or less than the delivery values given by the minimum angle of the swash plate, the pump delivery pressure PP is regulated by the pressure PLS+21 bar. Because the unloading valve opens when the differential pressure between the pumpdelivery pressure PPand the

PLS LS pressure becomesequivalent to the loading of the spring(2) (21 bar), thedifferential LS pressure LS becomes 21 bar.

CLSS (Closed Center Load Sensing System)

,PLS del

OPERATION

RKZ01750

Final control of control valve

• When final control are performed with the control valve, a pressure PLS is generated that pressurizing the spring chamber, acts on the left-hand extremity of the valve (1). The actuatorpressure isintroduced into the LScircuit and then into the spring chamber. As a result, the pump pressure PP tends to increase.

• When the differential pressure between the pump delivery pressure PP and the LS pressure PLS has the same value as the loading on the spring (2) (21 bar), the shuttle (1) moves to the left ( ) and the pump circuit PP puts itself into communication with the tank circuit T.

WB91R-2 WB93R-2

Consequently the exceeding pump delivery Q, relative to the actuator request, is sent to the tank circuit.

• The pump delivery pressure PP is regulated by the combination of the pressure provided by the spring (21 bar) and by the LS pressure PLS, i.e. when the pressure differential bar.

,PLS reaches the value of 21

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STRUCTURE AND FUNCTION

3. When therequest foroil flow from theactuators exceeds the minimum delivery of the pump duringuse of the control valve, the connection to the tank circuit is eliminated and the entire pump delivery Q is sent to the actuators.

CLSS (Closed Center Load Sensing System)

RKZ01760

OPERATION

When the control valve is in use

• When the control valve shuttle is operated to execute

a bigger stroke, the openingsection ofspool becomes bigger and consequently the controlled delivery. Because the control valve passage is large, the difference between the LS pressure PLS and the pump delivery pressure PP is reduced up to 18 bar (LS pump valve setting).

• Because the differential pressure between the pump

delivery pressure PP and the LS pressure PLS is not equal to the pressure given by the spring loading (2) (21 bar), the shuttle (1) is pushed to the right ( ) of thespring(2).

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• The result is that the connection between the pump delivery circuit PP and the tank circuit T is excluded and the entire pumpdelivery Q is sent to the actuators.

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STRUCTURE AND FUNCTION

INTRODUCTION OF THE LS PRESSURE

• The LS pressure is the pressure generated by external forces acting on the actuators at the outlet of the control valve.

CLSS (Closed Center Load Sensing System)

To the pump

RKZ01781

OPERATION

• When the shuttle (1) is activated, the pump pressure PP starts to flowinto the actuatorcircuit A through the duct b.

• At the same time the compensator (2) moves upwards ( ) so that the flow controlled by spool (1) can flow towards the actuator A. (Check valve (4) do not allow any flow up to when pressure in chamber c is higher than pressure in chamber b). Pressure downstream spool (1) flows in the PLS circuit downstream the compensator valve throught the orifice d.

WB91R-2 WB93R-2

• The PLS circuitoftheLS is thus in communication with the tank circuit T by means of the LS decompression valve (3). (See the description ofthe LS decompression valve).

• The system stabilizes when a pressure difference of 18 bar is generated across the shuttle (1) between pump pressure PP and PLS pressure.

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STRUCTURE AND FUNCTION

5. DELIVERY COMPENSATION

INTRODUCTION

The flow sent to each actuator is controlled by the opening area of each spool. While performing complex control, in traditional control valves the difference between actuators pressure might cause sudden and unexpected movements acceleration in those actuators operal at lower pressure. The adoptionof the pressure compensation valve allow to control those situation guaranting the proportionalitybetween each actuator.

FUNCTION

Compensation of actuator deliveries occurs when, during the simultaneous activation of two or more movements, the pressure of one actuator drops lower than thatof the other, and pump delivery, if not controlled, tends tobe supplied the actuator operating at lower. (In the diagram the actuator on the left is requesting higher pressure).

CLSS (Closed Center Load Sensing System)

PAV

PLS

PBV

OPERATION

1. When activating an actuator at a pressure lower than the one already working. (While operating actuator A starts operating actuator B)

• Until the pressure PBV downstream from the shuttle (1) reaches the same value requested by actuator B, no oil passes.

• When the pressure requested by actuator B is ex- ceeded, movement can commence. This creates a flow that adding to the one controlled by spool (3) reduces the pressure upstream of spool (1) and (3) and therefore the

• The pump compares the delivery pressures PP and PLS and senses that the difference

variation in ing the swash plate angle. (For the detail see «Hydraulic pump»).

,P between PLS and PP.

,P<18 bar. This

,P causes an increase in oil flow increas-

• Until the pump does not realizea til the increase in oil flow compensates the requirements of the two actuators, the pump will continue to increase delivery.

•

,P of 18 bar will stabilize as soon as it is restored to.

• The compensator(2) is moved upwards bythe oilflow and stops whenthe aperture betweenthe chambers a and b reduces the passage sufficiently to reduce the pressure in chamber b to be sent to the actuator.

10-64

RKZ02310

,P of 18 bar, i.e. un-

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STRUCTURE AND FUNCTION

2. When a low pressure actuator needs to work at a higher pressure than the other

CLSS (Closed Center Load Sensing System)

PAV

PLS

PBV

• If the actuator B needs to work at a higher pressure (PB>PA), the pressure PB will start to increase.

• Since pressurePB is increasing, thecompensator (2) moves upwards to restore the bers a and b, and therefore the stream or downstream from the shuttle (1).

• When pressure PB exceeds pressure PA,thecom- pensator (2) is fully open and the pressure PB is introduced into the LS circuit.

• TheincreaseinpressureintheLS circuit obliges the pump to increase delivery until the 18 bar.

,P between the cham-

,P does not vary up-

,P is restored to

RKZ02320

• Simultaneously the increase in pressure upstream from the shuttle (3) generates an increase in stream and downstream from the shuttle. (PAV<PLS<PP)

• Because the pressure PLSwhich is equalto the pres- sure PB acts on the upper side of the compensator (4), and since the pressure PAV is lower, the compensator (4) is pushed downwards.

• The compensator stops when the aperture between the chambers c and d generates a reduction of the passage sufficient to reduce the pressure to be sentto the actuator, and to increase the pressure PAV until the

,P is restored to the 18 bar necessary for equi-

librium.

,P up-

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STRUCTURE AND FUNCTION

3. When an increase in delivery is required by an actuator

CLSS (Closed Center Load Sensing System)

PAV

PLS

PBV

• When an increased delivery is required by actuator A, i.e. when the shuttle (3) is asked to execute a bigger movement, the section of the aperture increases.

• The increase in aperture provokes a drop in tween the two sides of the shuttles (2) and (3), because the flow, which has remained unchanged until now, is divided between both the actuators.

• At the same time the pump senses the variation in and increases the oil flow until the of 18 bar between the two sidesof theshuttle (1)and the compensator (4) changes position in order to restore the

,P upstream and downstream from the shuttle (3).

,P is restored to ,P

,P be-

RKZ02330

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STRUCTURE AND FUNCTION

6. “LIFD” CONTROL SYSTEM FUNCTION

• The Load IndependenceFlow Divider (LIFD) intervenes automatically when the oil-flow requestedby the actuators exceeds the maximum delivery guaranteed by the pump. In this case, the oil-flow is divided between the various actuators in proportion to their requirements.

CLSS (Closed Center Load Sensing System)

PCV

PBV

PAV

RKZ02340

OPERATION

• When, during the simultaneous operation of more than one actuator, one of them needs a higher pressure and the characteristics of the pump are exceeded, the pump guarantees a delivery limited by its calibration curve.

• At this point less oil than requested is distributedto all the actuators.

• Because the sections of the apertures remain unchanged, the pressure upstream and downstream from theshuttles drops. Since theposition ofthe compensator (4) is determined by the pressure of the LS signal, by the pressure PBV downstream from the shuttle (3) and by the flow of oil needed for the movement, the compensator is pushed downwards by the higher pressure in the upper chamber until the pres-

WB91R-2 WB93R-2

sure PBV downstream from the shuttle becomes equal to the pressure PAV downstream from the shuttle (1). This equalizes the pressure (1).

• Thus the flow of each actuator is reduced by a percentage equal to the reduction or absence of pump delivery.

• In other words, when the request for performance is excessive, the system can nevertheless guarantee proportionality and graduality for the movements in any load conditions.

• If an increase in delivery is requested, rather than an increase in pressure, and the characteristics of the pump are exceeded, the system will function in the same way as described for the above case.

,P of the shuttle

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STRUCTURE AND FUNCTION

CLSS (Closed Center Load Sensing System)

7. LS DECOMPRESSION VALVE DESCRIPTION

The LS decompression valve is a throttle that continuously releases a small quantity of oil from the LS circuit and that, when the shuttles are brought back to a neutral position, releases the residual LS pressure. This continued flow renders the PLS pressure increment more gentle and gradual, and increases stability and control during the phases of reducing the LS pressure..

Q(ᐍ / min)

1,3

RKZ02350

0,8

20 250

P (bar)

RKZ02360

OPERATION

• When the LS pressure reaches chamber a of the valve, it generates a force that opposes the force of thespring(2).

• Until the force generated by theLS pressure exceeds the force of the spring(2) (LSpressure low) the shuttle (1) remains «at rest» and oil flows through the calibrated orifice b in the tank circuit.

• When the force generated by the LS pressure ex- ceeds the force of the spring (2),the shuttle is pushed upwards ( ) and the passages c are closed. Oil continues to flow into thechamber duntil the force generated by the pressure contained in chamber d, together with the force of the spring (2), exceeds the force generated by the LS pressure.

10-68

• The shuttle is pushed downwards ( ) and passage c is opened.

• The system is in equilibrium(i.e. the shuttle is at rest), when the quantity of oil allowed to flow into the tank circuit is equivalent to the quantity that generates a pressure difference

(PLSxS)=[(PLS1xS)+F] where: PLS=LS pressure PLS1=LS pressure contained in chamber d S=section of the shuttle F=force of the spring

,P such that

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STRUCTURE AND FUNCTION

8. PRESSURE CUT-OFF VALVE

DESCRIPTION

The function of the pressure cut-off valve is to regulate the maximum pressure of the Load Sensing signal and hence also the pressure of the pump.

CLSS (Closed Center Load Sensing System)

RKZ01770

OPERATION

• The pressurized oil of the LS reaches the chamber a of the valve.

• When the force generated by the LS pressure on the valve (1) exceeds the force of the spring (2), the valve (1) is pushed upwards ( ) opening the passage between the chamber a and the tank circuit.

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STRUCTURE AND FUNCTION

9. PRIORITY VALVE (ONLY FOR THE 2-3 SPOOL CONTROL VALVE) FUNCTION

The function of thepriority valve is to distribute oil to the steering unit and tothe otherhydraulic components. Distribution is determined by the position of the valve of the priority valve in function of the LS signal, oil delivery from the pump, the pressure of the steering unit and thepressure ofthe hydrauliccircuit. The position of the valve issuch asto guaranteethat delivery to the steering unit will always correspond to the actual need.

CLSS (Closed Center Load Sensing System)

DLS

10-70

To the actuator

RKZ02371

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STRUCTURE AND FUNCTION

SOLENOID VALVE

Solenoid valve block ST1 - Differential locking - Backhoe boom locking

SOLENOID VALVE

RKZ04960

1. EV4 - Backhoe boom locking

2. EV3 - Differential locking

a. Port T - To the transmission

b. Port 1 - Boom-locking cylinder c. Port 2 - To the rear axle

d. Port P - From the transmission

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STRUCTURE AND FUNCTION

SAFETY VALVE

Shovel raise

a. Port Y - to the raising cylinders (Head side) b. Port A - From the shovel control valve (Port A1)

c. Port X - To the raising cylinders (Base side)

d. Port B - From the shovel control valve (Port B1)

Bucket Dump

a. Port Y - To the dump cylinders (Head side)

b. Port A - From the shovel control valve (Port B2) c. Port X - To the dump cylinders (Base side)

d. Port B - From the shovel control valve (Port A2)

Boom

a. Port Y - To the boom cylinder (Head side)

b. Port A - From the backhoe control valve

(Port A6)

c. Port X - To the boom cylinder (Base side) d. Port B - From the backhoe control valve

(Port B6)

RKZ00850

Arm

a. Port Y - To the arm cylinder (Head side) b. Port A - From the backhoe control valve

(Port B1)

c. Port X - To the arm cylinder (Base side)

d. Port B - From the backhoe control valve

(Port A1)

CHARACTERISTICS

Safety valve calibration Shovel dump: 230 bar Boom: 350 bar Arm: 230 bar

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WB91R-2 WB93R-2

Komatsu WB91-93 User Manual

CONTENTS

LIST OF REVISED PAGES

SAFETY

FOREWORD

HOW TO READ THE SHOP MANUAL

HOISTING INSTRUCTIONS

STANDARD TIGHTENING TORQUE

COAT I NG M ATER I A LS

ELECTRIC

WEIGHT TABLE

TABLE OF OIL AND COOLANT QUANTITIES

CONVERSION TABLE

STRUCTURE AND FUNCTION

POWER TRAIN

TRANSMISSION (4WD)

TRANSMISSION

DRIVE SHAFTS

CONTROL VALVE BLOCK

FRONT AXLE

REAR AXLE

HYDRAULIC PUMP

STEERING UNIT

HYDRA ULIC CIRCUIT

SHOVEL CONTROL VALVE

BACKHOE CONTROL VALVE

CLSS

SOLENOID VALVE

SAFETY VALVE